This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The specific scientific and technological objectives of this program are: A. Image based modeling and rapid prototyping manufacturing processes can produce two-dimensional (2D) and three-dimensional (3D) tissue mimicking models of the mouse and human cardiac anatomy. B. Standard chemical synthesis methodologies can produce engineered tissue mimicking materials (elastomers, hydrogels) that match the morphology and emulate the in vivo murine and human cardiac tissue mechanical and imaging characteristics. C. Mechanical properties of tissue engineered and murine cardiac myofibers can be accurately and precisely characterized ex-vivo. Specifically: C.1 There are non-significant differences between strain, stress, shear modulus of elasticity, Poisson ratio, density estimates, maximum force and tensile strength developed, of the synthesized tissue mimicking materials and the murine heart C.2 There are significant differences between local (tissue) and global (organ) estimates of tissue elasticity of the fixed murine heart, determined by atomic force microscopy D. Constitutive law behavior of engineered tissue mimicking materials and the in vivo heart, can be accurately and precisely computed with model-based 3D- and 4D-computational techniques using MRI, and validated under dynamic conditions using a multimodality cardiac phantom and in vivo.